1. Field of the Invention
The present invention relates to a core yarn production method and apparatus, which ensures that a core fiber is included in a core yarn.
2. Description of the Background Art
An exemplary apparatus for producing a core yarn having an elastic core fiber provided in a bundle of fibers is a core yarn production apparatus as disclosed in Japanese Laid-Open Patent Publication No. 2002-363834 (“air sucker device 58” in FIG. 4 and paragraph 0035). The production apparatus uses an elastic fiber as a core fiber, which is supplied from an elastic core fiber supply device, and a bundle of fibers as a covering fiber, which is drafted by a drafting device, and produces a core yarn by performing air spinning using a spinning device. The elastic core fiber supply device includes an air sucker device from which a jet of high pressure air is emitted to merge the elastic core fiber with the bundle of fibers.
In the case of producing a fine count core yarn with the above-described core yarn production apparatus, however, the amount of sliver that is supplied to the drafting device is low, resulting in a bundle of fibers having a narrow width, and the bundle of fibers in the drafting device may be disturbed due to the high pressure air from the air sucker device, so that the bundle of fibers fails in catching and merging with the core fiber from the core fiber supply device. This often causes the core fiber to wrap around the front bottom roller (which is called “bottom wrap”), so that a yarn having no core fiber is taken up onto a package.